Many techniques exist for resuscitating a patient suffering from a life threatening condition. Patient conditions that may require resuscitation include, but are not limited to, cardiac arrest, bradycardia, tachycardia, ventricular fibrillation and respiratory arrest. One example of a technique for resuscitating a patient is to use an electric defibrillator to apply electrical energy to the patient.
The human heart contracts when stimulated by an intrinsic electric impulse generated by the human body itself. When a patient undergoes some form of cardiac arrest, or where the heart has stopped beating or is beating at an unsafe rate, it is often valuable to apply an unnatural electrical impulse to restart or sync a human heart so that it can continue to function and thus keep a patient alive. Electrical impulse therapy is often administered using an electric defibrillator. An electric defibrillator typically includes a power source and at least two defibrillation electrodes that provide a connection with the skin of a patient for electricity to be administered to the patient. Typically, defibrillation electrodes are disposed upon the chest region of a patient such that electrical energy can be administered to the patient.
Portable versions of electric defibrillators have existed since the 1960's. The use of these devices is now widespread. Both emergency and non-emergency personnel often have access to portable versions of electric defibrillators, known as automated external defibrillators (AEDs), in case of emergencies. Examples of such AEDs include: Cardiac Science's Powerheart®, Medtronic's LIFEPAK®, Defibtech's Lifeline™, Phillips' HeartStart™, and Zoll's AED Plus®.
It is important that these AEDs be continuously operational and ready for use on a moment's notice. Any delay in the ability of a rescuer to use such a device in an emergency can mean the difference between life and death for a patient. One such delay may occur as a result of the defibrillation electrodes being frozen. Because AEDs are highly portable, they are often stored in automobiles or other unheated places. In cold weather, portions of the defibrillation electrodes may freeze. In order for a defibrillation electrode to properly deliver an appropriate electrical impulse as described, the electrode must not be frozen. In current practice, if an electrode is frozen, a rescuer must either replace the electrode with an unfrozen one, or use external means such as a heater to thaw the electrode. Often, in critical situations, a frozen electrode results in valuable time wasted and in the worst case may result in death to a patient.